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concept IModel: Concept I
Battery: 9 volt
Adapter: AC9180
Year: 1976
Chip: TMS0972 
Manual:
with permission www.datamath.org
Info: The Zayre CONCEPT Calculator Series culminated in June 1976 with the introduction of the Texas Instruments CONCEPT I, CONCEPT II, and CONCEPT III calculators based on the TI-1200, TI-1250, resp. SR-16 II but disappeared already in August 1979 with the clearance sales of the CONCEPT COMPACT calculators.